Question

Four gases A, B, C, and D have critical temperatures of $32°C,-118°C,31.1°C,–140°C$, respectively. Arrange them in the increasing order of ease of liquefaction of the gases

• A. D<B<C<A
• B. A>B>D>C
• C. C<D<B<A
• D. A<C<B<D

Answer 1

The correct option is A

D<B<C<A

Explanation for Correct option: (A)

1. The force of attraction is a force that draws two or more bodies together.
2. The critical temperature of a substance is the temperature at which its vapour cannot be liquefied, regardless of how much pressure is applied.
3. A critical temperature exists for every substance.
4. The force of attraction between molecules is represented by the critical temperature.
5. The intermolecular force of attraction increases as the critical temperature rises, making liquefaction of the gas easier.
6. Thus, gas A will liquefy easily as it has the highest temperature among the other gases; after gas A, gas C will liquefy faster than gas B and gas D. After gas C, gas B will liquefy easily and then gas D will liquefy; i.e D<B<C<A.

Conclusion: Hence, option (A) is correct.